This invention relates to limited rotation electromechanical actuators that have so-called moving iron rotors.
In actuators of this type, a permeable rotor assembly defines rotor pole faces and is mounted to rotate relative to a stator assembly. The stator assembly has a pair of pole pieces (each having a pair of stator pole faces arranged around the rotor axis) and a permanent magnet which imposes a biasing flux through the pole pieces and the rotor assembly via corresponding pairs of the rotor and stator pole faces. Typically the angular excursion is limited to a peak-to-peak excursion of about 60.degree..